What woulb be the best throttle for my built h22 turbo, I have GE intake manifold it also has ramhorn turbo manifold with a gt40 turbo i was wondering if 70mm throttle body would be good enough and also if there is a big difference between 70mm and 75mm

 

It depends on your piping size. If you are running a 2.5 inch pipe, then there is not need for a 75mm throttle. Get the size that matches or is slightly larger than your piping. You don't want to have restriction at the throttle, but having a throttle body that is too big will cause poor throttle response near WOT.

 

I'm using a 2.5 piping

 

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whats the biggest TB that a GE can accept? care to share some dyno numbers?

 

Like I said, run a tb the same size or a little larger than your piping for good throttle response and flow. It's not hard...

2.5 inches X 25.4mm/inch = 63.5mm

Go with something a little larger, or if you plan on changing your piping to a 3 inch, then

3" X 25.4mm/inch = 76.2 mm

If this is the case, then get the 75mm. If you are not going to upgrade your piping, get a smaller one and save yourself money and enjoy the better top end throttle response.

Out.